640155035620 has 24 divisors (see below), whose sum is σ = 1344363733944. Its totient is φ = 256054745856.

The previous prime is 640155035593. The next prime is 640155035633. The reversal of 640155035620 is 26530551046.

It can be written as a sum of positive squares in 4 ways, for example, as 152582421924 + 487572613696 = 390618^2 + 698264^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 640155035620.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 298342 + ... + 1170178.

It is an arithmetic number, because the mean of its divisors is an integer number (56015155581).

Almost surely, 2^640155035620 is an apocalyptic number.

It is an amenable number.

640155035620 is an abundant number, since it is smaller than the sum of its proper divisors (704208698324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640155035620 is a wasteful number, since it uses less digits than its factorization.

640155035620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 908559 (or 908557 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 37.

Adding to 640155035620 its reverse (26530551046), we get a palindrome (666685586666).

The spelling of 640155035620 in words is "six hundred forty billion, one hundred fifty-five million, thirty-five thousand, six hundred twenty".